Remote control system



March 15, 1960 H. HURLIMANN ETAL 2,928,957

REMOTE CONTROL SYSTEM Filed Nov. 26, 1956 United States Patent REMOTE CONTROL SYSTEM Application November 26, 1956, Serial No. 624,409

Claims priority, application Switzerland November 26, 1955 7 Claims. (Cl. 307-140) Central remote control installations, also called broadcast control installations, serve to send switching orders from a control station through an electric energy distribution network to all load points of the network, either for changing over the tariff of meters, or for switching on and oil loads, for example boilers, furnaces, street lighting and the like, or for controlling oil-break switches. It is known for this purpose to transmit audio-frequency impulses to the network from a transmitter at the control station, the stations to be controlled comprising receivers which respond to predetermined signals and carry out the required switching operations. The most common of the various known central remote control systems are based on the time interval method, in which a series of order impulses follow a starter impulse on the time axis. These order impulses are usually generated by a synchronous selector acting as an emitter which acts in known manner, through an audio-frequency sending installation, on the energy transmitter network to be controlled. The receivers are generally selectors which run synchronously with the mains frequency and whose selecting contacts correspond to the contacts of the synchronous emitter. It is in combination with this known remote control system that the present invention preferably operates although the invention is also suitable for use with other systems employing similar principles.

In the accompanying drawings:

Figs. 1 and 2 show impulse diagrams of the time interval method; and v Fig. 3 shows diagrammatically an arrangement according to the invention. For simplicity the customary synchronous selector, associated switching relays, and the loads are not shown.

Fig. 1 shows by way of example in known manner the starter impulse s, then a group a, b, c and d for impulsecombination orders, and thereafter the direct order series of signals 1, 2, 3, 4, 5 comprising double-signal order pairs E, A.

The direct orders are known as such because they directly initiate the desired switching operations through the associated synchronous selecting contacts. Alternatively, a desired control operation may be initiated by Way of a grouping of a number of order impulses in known manner, for example with the aid of the groups a, b, c and d, in accordance with Fig. 1.

In the case of direct order control it is desirable to reduce the direct order series to the greatest possible simplicity. This is based primarily on the fact that the direct order series can then always be clearly repeated without omissions, especially when the direct order series is arranged in known manner in accordance with doublesignal pairs. In the combination or group selection, this possibility of simple repetition does not exist, and since a particular impulse combination is associated with each order it is necessary to transmit the entire group for each individual order. The impulse diagram A of Fig. 2 shows a section of a repetition process of a direct order series arranged in accordance with the double-signal ice method. The impulse diagram B shows the corresponding section, in which, however, the repetition impulses of the double signals 8 and 9 have been suppressed to initiate certain special orders, an operation with which the present invention is concerned.

Special orders can be initiated by such suppression and by similar variations of the direct-order normal repetition programme. As can be seen from Fig. 2, such special orders have the sometimes very important property that a particular special order can be immediately carried out during the performance of a normal order programme by introducing variations in said program.

The present invention is therefore concerned with a method of remotely controlling electric switching devices by means of mains super-position central remote control installations, also called broadcast control installations, which operate in accordance with the synchronous selector principle, that is to say, in which order impulses associated in time with a starter impulse are sent, said invention being characterized by the fact that there is employed at the receiving station an arrangement which so co-operates with the direct-order normal repetition programme that on arrival of the normal train of order impulses the actuation of at least one auxiliary contact provided for special purposes is prevented, but that on suppression of at least one of a number of successive impulses of the normal order programme series the preventive action is cancelled for the purpose of initiating special orders.

The method according to the invention will be more fully explained with reference to Fig. 3. In the transmission of a normal order series, a synchronous motor S is started in a manner known per se by the starter impulse through an input circuit R and the contact r thereof, and is kept in movement for a particular time by means of the cam n. This is a known circuit arrangement. To implement the principles of the invention there is mounted on the shaft of the synchronous motor S to form a coupling element a ratchet wheel KR, which is arranged to act through a pawl K on a loose cam P mounted on the shaft of the synchronous motor S, which cam closes an auxiliary circuit p when sufiiciently r0- tated. On arrival of order impulses, the pawl K is displaced by means of an impulse relay M, so that the ratchet wheel no longer acts on the cam P. If, however, at least one of a number of successive repetition impulses is suppressed in the otherwise normal repetition impulse series, for example the impulses 8 and 9 in Fig. 2, the cam P is rotated by the pawl K until the auxiliary contact p is closed due to the rotation of the ratchet wheel KR in the direction indicated by the arrow. Due to the closing of the auxiliary contact p the relay F has been energized, the said relay being designed, for example, as a change-over relay, so that the object E to be controlled is placed in the circuit thus implementing the special order caused by suppression of a normal control order.

The tooth form of the ratchet wheel KR and of the pawl K is such that after a predetermined rotation the pawl K is disengaged with the aid of the spring F and engages with the next tooth so that the cam P again bears against the stop G. The system constants are designed such that the cam P is not sufficiently rotated to actuate contact p during the intervals between normally occurring order impulses but is sufficiently rotated when these intervals are extended by suppression of an order impulse.

The ratchet wheel KR can be interrupted in its coupling action on the cam disc P for particular sections of the impulse programme by appropriate design, for example, by removal of a number of teeth. This is desirable, for example, in passing through an impulse section which is allocated to group formation, that is to say, in those intervals in which consequently the utilisation of were modifications of the repetition series is not possible to the extent necessary to effect special switching.

The method according to the invention is particularly important inter alia when an immediate special order is to be initiated at any time, for example during the transmission of a normal order programme. This is required, for example, for air-raid protection purposes, where it must be possible at any time to actuate an air-raid alarm arrangement within a few seconds. Such an alarm arrangement may be, for example, a special remote control receiving arrangement, as indicated by E in Fig. 3.

Since it would in some cases be desirable to prevent the initiation of a special order by the method according to the invention at certain times, there may be employed, as shown in Fig.3, a further receiving arrangement E which is designed, for example, as a group receiver and which only permits operation through the circuit of the auxiliary contact p after the closing of a contact k.

What we claim is:

1. Apparatus for sensing variations in the normal order impulse series. in mains-superposition central remote control installations and for responding to said variations comprising sensing means responsive to said order impulse configuration, control means adjusted in accordance with normal impulse configurations and responsive to said sensing means, actuating means responsive to said control means, said control means driving said actuating means when said sensing means responds to variations in the normal impulse configuration.

2. Apparatus in accordance with claim 1 in which said sensing means is responsive to predetermined intervals in said order impulse configuration.

3. Apparatus in accordance with claim 1 in which said actuating means contains a circuit responsive to order impulses.

4. Apparatus in accordance with claim 1 in which said sensing means comprises a solenoid means, engaging mechanism, coupling means and driving means and wherein said coupling means is engaged to said driving means for a predetermined period by said engaging mechanism during the impulse configuration period when there is an absence of impulses, said engaging mechanism being thus controlled by said solenoid means which is respontive to said control impulse configuration.

5. Apparatus according to claim 1 in which said control means is a cam and said actuating means is a switch responsive to said cam, said cam having a configuration such that rotation during normal intervals between impulses is not sufficient to actuate said switch but is suflicient when said interval is greater than normal.

6. Apparatus for sensing variations in the normal order impulse series in mains-superposition central remote control installations and for responding to said variations comprising controllable integrating means, control means responsive to said order impulse series and operable to activate and deactivate said integrating means, actuating means responsive to said integrating means and ope crable to initiate the special switching when said integrating means achieves a predetermined status.

7. Apparatus, according to claim 6, including preset supercontrol means embodied in said integrating means. and operable to render said integrating means inoperative during predetermined intervals and also operable to render said integrating means repetitively operative.

References Cited in the file of this patent UNITED STATES PATENTS 

